a-a a-b aaa aab aad aae aah aao ab- aba abb abd abe abh abo ad- ada adb add ade adh ado aea aeb aed aee aeh aeo aha ahb ahd ahe ahh aho aoa aob aod aoe aoh aoo baa bab bad bae bah bao bba bbb bbd bbe bbh bbo bda bdb bdd bde bdh bdo be- bea beb bed bee beh beo bha bhb bhd bhe bhh bho boa bob bod boe boh boo daa dab dad dae dah dao dba dbb dbd dbe dbh dbo dda ddb ddd dde ddh ddo de- dea deb ded dee deh deo dh- dha dhb dhd dhe dhh dho doa dob dod doe doh doo eaa eab ead eae eah eao eba ebb ebd ebe ebh ebo ed- eda edb edd ede edh edo eea eeb eed eee eeo eha ehb ehd ehe ehh eho eo- eoa eob eod eoe eoh eoo haa hab had hae hah hao hba hbb hbd hbe hbh hbo hda hdb hdd hde hdh hdo he- hea heb hed hee heh heo hha hhb hhd hhe hhh hho hoa hob hod hoe hoh hoo oaa oab oad oae oah oao ob- oba obb obd obe obh obo oda odb odd ode odh odo oea oeb oed oee oeh oeo oha ohd ohe ohh oho oo- ooa oob ood ooh ooo